Thanks for clarifying, I couldn't understand why you'd pay £15 for a cable, if you didn't notice any difference.
Like you I generally go for a "well-made" looking, well shielded anologue/digital interconnect, same with speaker cable, and I also don't like to spend too much, if money was no option I'd probably pay more. Can't comment on mains cable, though have been tempted to try a cheap one out, just to hear if there's any difference for myself (and at least it would make it easier to identify which mains lead belongs to which device if nothing else). To be honest, when I bought my rack I did think it made a slight difference to the sound, but could have just imagined it but I didn't buy the rack for any sound improvements I just bought it as I was running out of space to keep everything!